Abstract
Poor crop stand is a common problem in saline areas. Germination and seedling emergence may be depressed as a result of impeded aeration, saline or dry conditions. In this study, we examined the effects of salinity and moisture stress and their interactions on seed germination and seedling growth of carrots. Variable soil matric and osmotic potentials were either obtained by equilibrating soil salinized to different degrees on a 0.5 MPa ceramic plate soil moisture extractor or by adding different amounts of salt solutions to the same mass of air-dried soil, based on a previously determined soil moisture release curve, and allowing to equilibrate for 1 week.
Germination decreased significantly in the investigated silty soil (Aquic Ustifluvent) at soil moisture potentials higher than −0.01 MPa, whereas osmotic potentials as low as −0.5 MPa did not influence germination. Matric potentials of −0.3 and −0.4 MPa, respectively, resulted in a strong decrease (35–95%) of germination and delayed germination by 2 to 5 days in the silty soil to which different amounts (18 and 36%, respectively) and sizes (0.8–1.2 mm and 1.5–2.2 mm, respectively) of sand particles had been added. No effect of sand and grain diameter was detected. Germination was not affected by comparable osmotic potentials.
Seedling growth showed a much higher sensitivity than germination to decreasing matric potentials, but was not affected by osmotic potentials ranging from −0.05 to −0.5 MPa. Optimum shoot growth occurred at matric potentials between −0.025 and −0.1 MPa. Shoot and root growth decreased markedly at matric potentials higher than −0.01 MPa. Fresh weight of shoots decreased gradually at matric potentials lower than −0.2 MPa. Root growth was significantly increased at matric potentials of −0.1 to −0.3 MPa, whereas comparable osmotic potentials did not have equivalent effects.
It is concluded that germination and seedling growth are differently affected by comparable matric and osmotic stresses and that water stress exerts a more negative effect than salt stress.
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References
Bresler E L, McNeal B L and Carter D L 1982 Saline and Sodic Soils: Principles-Dynamics-Modelling. Springer-Verlag, Berlin.
Childs S W and Hanks R J 1975 Model of soil salinity effects on crop growth. Soil Sci. Soc. Am. Proc. 39, 617–622.
Collis-George N and Sands J E 1962 Comparison of the effects of the physical and chemical components of soil water energy on seed germination. Aust. J. Agric. Res. 13, 575–584.
Cowan I R 1965 Transport of water in the soil-plant-atmosphere system. J. Appl. Ecol. 2, 221–239.
Gardner W R 1960 Dynamic aspects of water availability to plants. Soil Sci. 89, 63–73.
Hillel D 1980 Applications of Soil Physics. Academic Press, New York.
Kennedy R A, Barrett S C H, Van derZee D and Rumpho M E 1980 Germination and seedling growth under anaerobic conditions in Echinochloa crus-galli. Plant Cell Environ. 3, 243–248.
McWilliam J R and Phillips P J 1971 Effect of osmotic and matric potentials on the availability of water for seed germination. Aust. J. Biol. Sci. 24, 423–431.
Passioura J B and Frere M H 1967 Numerical analysis of the convection and diffusion of solutes to roots. Aust. J. Soil Res. 5, 149–159.
Pasternak D M, Twersky M and deMalach Y 1979 Salt resistance in agricultural crops. In Stress Physiology in Crop Plants. Eds. HMussell and R CStaples. pp 127–142. Wiley, New York.
Richards L A and Wadleigh C H 1952 Soil water and plant growth. In Agron. Monograph 2. Ed. B TShaw. Academic Press, New York.
Roundy B A, Young J A and Evans R A 1985 Germination of basin wildrye and tall wheatgrass in relation to osmotic and matric potential. Agron. J. 77, 129–135.
Schmidhalter U and Oertli J J 1986 Influence of matric and osmotic potentials on germination and seedling growth. Trans. XIII Cong. of the Int. Soc. of Soil Sci 2. pp 153–154. Hamburg.
Schmidhalter U, Evéquoz M and Oertli J J 1988 Adaptive mechanisms of root growth under drought stress. In Plant Roots and Their Environment. Abstracts Int. Soc. Root Research. pp 27–28. Uppsala.
Schneider E C and Gupta S C 1985 Corn emergence as influenced by soil temperature, matric potential, and aggregate size distribution. Soil Sci. Am. J. 49, 415–422.
Sepaskhah A R and Boersma L 1979 Shoot and root growth of wheat seedlings exposed to several levels of matric potential and NaCl induced osmotic potential of soil water. Agron. J. 71, 746–752.
Sharma M L 1976 Interaction of water potential and temperature effects on germination of three semi-arid plant species. Agron. J. 68, 390–394.
Sharp R E and Davies W J 1979 Solute regulation and growth by roots and shoots of water-stressed maize plants. Planta 147, 43–49.
Taylor A G, Motes J E and Kirkham M B 1982 Osmotic regulation in germinating tomato seedlings. J. Am. Soc. Hortic. Sci. 107, 387–390.
Wadleigh C H and Ayers A D 1945 Growth and biochemical composition of bean plants as conditioned by soil moisture tension and salt concentration. Plant Physiol. 20, 106–132.
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Schmidhalter, U., Oertli, J.J. Germination and seedling growth of carrots under salinity and moisture stress. Plant Soil 132, 243–251 (1991). https://doi.org/10.1007/BF00010405
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DOI: https://doi.org/10.1007/BF00010405